• BIRD;
  • FT-ICR;
  • unimolecular dissociation;
  • dissociation kinetics;
  • dissociation thermochemistry


 II.Brief History of the Development of BIRD129
    1.  Dissociation by Ambient Radiation129
    2.  The Rapid-Exchange Limit129
  III.Experimental Approaches130
  IV.Fundamental Principles and Approaches to Interpretation131
 A.  Kinetics Considerations132
 B.  Large Molecules134
    1.  When Is the Large-Molecules Limit Achieved?135
    2.  Small Molecules137
    3.  Intermediate Size138
 V.Examples and Applications140
 A.  Proton-Bound Dimers140
 B.  Solvent Detachment Studies142
    1.  Small Solvated Ions142
    2.  Deuteration Effects142
    3.  Hydrated Metal Ions143
    4.  Non-Aqueous Solvents: Ru(bipy)+23 Complexes143
 C.  Silanes145
 D.  Zwitterions and Salt Bridges146
 E.  Metal-Cationized Amino Acids147
 F.  Macrocycles148
    1.  Iron Porphyrin Complexes148
    2.  Hemoglobin/Myoglobin148
 G.  Nucleotides and Oligonucleotides149
 H.  Protein and Polypeptide Ions149
 I.  Protein Complexes149
 J.  Informative Fragmentations by BIRD Excitation149
 K.  Analyzing Ion Mixtures150
 VI.Water-Cluster Ions150
 VII.Extensions and Analogs to BIRD for Activation Energy Measurement151
 A.  High-Pressure Thermal Dissociation152
    1.  Quadrupole Trap152
    2.  Hot Reaction Zones in the Ion Source152
 B.  Hot Filament Quasi-BIRD153
 C.  Laser IRMPD154
 D.  Conclusion154

Blackbody infrared radiative dissociation (BIRD) describes the observation of ion-dissociation reactions at essentially zero pressure by the ambient blackbody radiation field, which is usually studied in the ion-trapping ion cyclotron resonance (ICR) mass spectrometer. A brief summary of the historical context and evolution is provided. Focussing on the quantitative observation of the temperature dependence of BIRD rates, methods are developed for connecting BIRD observations with activation parameters and dissociation thermochemistry. Three regimes are differentiated and described, comprising large molecules, small molecules, and intermediate-sized molecules. The different approaches to interpreting BIRD kinetics in those three regimes are discussed. In less than a decade since its inception, this approach to studying gas-phase ions has spread over a wide variety of applications, which are surveyed. Some major areas of activity are: the characterization of solvent–molecule detachment from solvated ions; dissociation reactions of biomolecules (polypeptides, oligonucleotides, complexes involving polysaccharides) and the structural information to be deduced from them; and dissociations of proton-bound and metal–ion-containing complexes. Studies of blackbody-radiation-driven evaporation of water molecules from large water-cluster ions are surveyed briefly. Several techniques related to BIRD are noted, including collisional dissociation in the FT-ICR ion trap; high-pressure thermal dissociation in quadrupole ion traps and in heated inlet capillary regions; hot-filament-assisted dissociation; and infrared multiphoton dissociation (IRMPD). © 2003 Wiley Periodicals, Inc., Mass Spec Rev 23:127–158, 2004.